Introduction: Occlusal veneer are considered promising solutions for coronal tooth structure loss. Pressed lithium di-silicate is the first choice indirect restorative material. Resin cements are the weak point in this biomimetic solution.
Objectives: Investigate the fracture resistance and shear bond strength of lithium di-silicate occlusal veneer using different dual cured resin cements.
Materials and Methods: 28 sound extracted human permanent molars were used. They were divided into 2 groups (n=14) according to 2 different tooth preparation. For group A the occlusal surface was anatomically reduced for fracture resistance test, while for group B the occlusal surface was flattened for shear bond strength test. Each group was divided into subgroups (n=7) according to resin cement system type used. For group A1 and B1, Panavia F 2.0 self-etch resin cement. While for group A2, B2 Variolink Ethetics total etch resin cement was used. lithium disilicate veneers (1mm) and discs (2×4 mm) were cemented according to manufacturer's instructions. Bonded samples were tested for fracture resistance and shear bond strength after thermocycling. Failure mode was determined. The data were statistically analyzed (p≤0.05).
RESULTS: Type of resin cement had a statistically significant difference on the fracture resistance and shear bond strength with P ≤ 0.05. Group (A2) Total etch Variolink Esthetic resin cement provided higher fracture strength (2259.5 N).Also, Group (B2) provided higher bond strength (34.36 MPa).
Conclusion: The lithium disilicate occlusal veneers are preferred using total etch adhesive to get the best bond strength and fracture resistance sufficient to withstand loading in molar region.